Effect of stiffness contrast on the dislocation equilibrium positions in a multi-layered structure

Abstract

The equilibrium positions of two edge dislocations lying in the same gliding plane have been theoretically determined in a structure composed of a thin layer embedded in an infinite-size matrix of different elastic constants, when the two dislocations are symmetrically distributed with respect to the axis of symmetry of the problem parallel to the interfaces. When the Burgers vectors of the two dislocations are equal and the matrix is stiffer than the layer, the equilibrium positions have been found to be unstable in the central layer and stable in the matrix. No equilibrium position is found when the matrix is softer than the layer. When the Burgers vectors are of opposite sign (same norm and direction) and the layer is stiffer than the matrix, the equilibrium positions are stable in the central layer and unstable in the matrix, no equilibrium position being found when the layer is softer than the matrix.